Printed guide books and booklets are used for a variety of purposes, including travel guides, dictionaries, collectible guides, and other reference books. The vast majority of guide books are published as bound books, using traditional binding techniques. This is acceptable for most purposes since the intent is to provide the reader with a complete set of information. One of the problems however, is that the reader is typically required to then carry the complete book with them, wherever they feel they may need to refer to that book. The reader may typically also have to search an index or a set of content pages to find the particular portion of the book they are interested in at that moment in time. Some people may choose to bookmark or use tabs to mark pages of particular interest, but even then they will have to search through their tabbed and marked pages, overlooking all of the other pages; and of course the addition of bookmarks and tabs adds to the overall size, weight, and bulk of the book.
The problem of book size is particularly acute with regard to travel guides and similar travel or activity-oriented guide books. Many readers like to plan trips in advance, so favor a larger guide book, with a greater variety of listings, and more detailed information about each listing. However, once having made their travel plans and on the road the reader is typically more interested in having information about their planned itinerary, and is unlikely to need the additional information a large guide book provides. The travel publication industry has responded by publishing both larger and more detailed guidebooks that one might read in their hotel, and pocket-sized books that one might carry. One problem with this approach is that there is rarely any consistent overlap between the listings in each of the variety of books, so that readers often end up taking both books along anyway, which simply exacerbates the problem.